The Centers for Disease Control and Prevention (CDC) says that a preliminary COVID-19 vaccine “safety signal” has been identified and is investigating whether the Bivalent Pfizer-BioNTech vaccine creates an increased risk of ischemic stroke in people 65 and older, Fox News reports.

In the statement, the CDC said that the preliminary signal hasn’t been identified with the Bivalent Moderna COVID-19 vaccine.

“Following the availability and use of the updated (bivalent) COVID-19 vaccines, CDC’s Vaccine Safety Datalink (VSD), a near real-time surveillance system, met the statistical criteria to prompt additional investigation into whether there was a safety concern for ischemic stroke in people ages 65 and older who received the Pfizer-BioNTech COVID-19 Vaccine, Bivalent,” the CDC said.

“Rapid-response investigation of the signal in the VSD raised a question of whether people 65 and older who have received the Pfizer-BioNTech COVID-19 Vaccine, Bivalent were more likely to have an ischemic stroke in the 21 days following vaccination compared with days 22-44 following vaccination.”

According to the CDC, an ischemic stroke “occurs when blood clots or other particles block the blood vessels to the brain.”

In the statement, the CDC pointed out that a large study of updated bivalent vaccines from Pfizer-BioNTech “using the Centers for Medicare and Medicaid Services database revealed no increased risk of ischemic stroke.” The agency also said that the Vaccine Adverse Event Reporting System (VAERS) managed by CDC and FDA has not seen an increase in reporting of ischemic strokes following the updated (bivalent) vaccine.

Source: Matzav